Patent GB-773865-A (GB)
Title: Improvements in or relating to programme setting apparatus
IPC: G04B23/06
Filed: 1955-12-07
Abstract: 773,865. Time-alarm signals. NILSON, C. E. J. Dec. 7, 1955 [Dec. 7, 1954], No. 35198/55. Drawings to Specification. Class 118 (2). Apparatus for actuating other apparatus or signals, electrically or mechanically, in accordance with a preset programme comprises a plurality of parallel bars carried in a framework so as to be individually displaceable longitudinally when in their free position but also each capable of being lifted against the action of springs, in a direction perpendicular to their length, to a position wherein they are locked against longitudinal movement. Each bar carries along its length a series of studs all projecting downwardly and in the frame below the bars is carried a plurality of similar square plates each slidable in slots such that an upper edge can abut respective studs on the bars when the particular plate is raised, thereby lifting the said bars into their locked positions. Each plate has a large central aperture and through the assembly of plates passes a spindle carrying a series of cams which may engage with respective inward projections from the plate apertures. The cam at one end of the sequence is driven by a ratchet-wheel stepped round by a pawl coupled to the armature of an electromagnet which is energized by pulses from a regulating clock. The first ten plates are raised respectively one each minute; the next cam is then moved one step in known manner such that the next six plates are raised respectively each ten minutes; the next cam is then stepped (i.e. at the end of an hour) and thus the next twelve plates are raised respectively each hour. A further set of two plates and cams is provided such that one plate is kept raised during the morning twelve hour period and the other during the afternoon twelve-hour period. A set of seven plates are similarly arranged to be raised respectively each twenty-four hours and represent days of the week. An extra downwardly-depending stud is provided on each bar to co-operate (when the bar is in its lower position) with a bridging member which is oscillated upon each energization of the driving electromagnet in an attempt to move the bars longitudinally. This can only occur if some of the projecting studs on a bar are removed so that the plates raised at a particular time cannot move that bar into its upper locked position. Thus, by removal of selected studs from a bar that bar is moved longitudinally at any predetermined time and day. Further studs on the bars are provided to contact bridge members and operate electric switches whenever a bar is moved longitudinally, and thereby, for example, give time signals in a factory. A plurality of switches are provided, each having an associated bridge member, such that different signals may be given in different parts of the factory. Semiautomatic changing of the signals for holidays is provided by two further square plates at the end of the assembly together with a slidable bar that holds one or the other plate in its raised position, thereby respectively locking all the bars preset to give normal working signals or all those bars preset for special holiday signals. The slidable bar can be set manually to a position wherein it is engaged by a ratchet-wheel on the end of the day-shift cam and is thereby moved after one day to change-over the plates and set the device for special holiday signals. After two days the bar moves to change back the plates and restore normal signalling. The device may be driven by an electric motor or mechanical clock movement instead of by electrical impulses.